Transformation of TNT to Triaminotoluene by Mixed Cultures Incubated Under Methanogenic Conditions

摘要

2,4,6-Trinitrotoluene (TNT) is an explosive widely used by the military. Although it is no longer manufactured in the United States, large amounts of wastewater are generated annually from load, assembly, and packing (LAP), and demilitarization operations. Granular activated carbon adsorption is the standard technology for treating wastewater containing TNT and maintaining discharges within the limits established under the National Pollutant Discharge Elimination System. Previous studies evaluating biological treatment of pink water using anaerobic fluidized bed granular activated carbon bioreactors have been promising. Our objectives for this work were to study the end-products produced during the anaerobic biodegradation of TNT and study the effect of adding cosubstrates on TNT degradation. These studies demonstrated TNT was initially reduced to a variety of reduction products that culminated in the formation of triaminotoluene (TAT). TAT was susceptible to further degradation under anaerobic conditions, but its fate was not determined. The addition of ethanol and glucose enhanced the degradation of TNT, but acetate did not. These studies demonstrate, for the first time, near stoichiometric formation of TAT in a mixed culture incubated under methanogenic conditions, and demonstrate the importance of adding reduced cosubstrates to enhance the formation of TAT.